diff options
| -rw-r--r-- | arch/powerpc/Kconfig | 1 | ||||
| -rw-r--r-- | arch/powerpc/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/powerpc/kernel/kprobes.c | 65 | ||||
| -rw-r--r-- | arch/powerpc/kernel/optprobes.c | 2 | ||||
| -rw-r--r-- | arch/powerpc/kernel/rethook.c | 73 | ||||
| -rw-r--r-- | arch/powerpc/kernel/stacktrace.c | 6 |
6 files changed, 81 insertions, 67 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index b9f11c262582..1f9d23b276b5 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -269,6 +269,7 @@ config PPC select HAVE_PERF_EVENTS_NMI if PPC64 select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP + select HAVE_RETHOOK if KPROBES select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_RELIABLE_STACKTRACE select HAVE_RSEQ diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index 1784b6a6ca1d..f43c1198768c 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -139,6 +139,7 @@ obj-$(CONFIG_KPROBES) += kprobes.o obj-$(CONFIG_OPTPROBES) += optprobes.o optprobes_head.o obj-$(CONFIG_KPROBES_ON_FTRACE) += kprobes-ftrace.o obj-$(CONFIG_UPROBES) += uprobes.o +obj-$(CONFIG_RETHOOK) += rethook.o obj-$(CONFIG_PPC_UDBG_16550) += legacy_serial.o udbg_16550.o obj-$(CONFIG_SWIOTLB) += dma-swiotlb.o obj-$(CONFIG_ARCH_HAS_DMA_SET_MASK) += dma-mask.o diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 14c5ddec3056..f8aa91bc3b17 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -228,16 +228,6 @@ static nokprobe_inline void set_current_kprobe(struct kprobe *p, struct pt_regs kcb->kprobe_saved_msr = regs->msr; } -void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs) -{ - ri->ret_addr = (kprobe_opcode_t *)regs->link; - ri->fp = NULL; - - /* Replace the return addr with trampoline addr */ - regs->link = (unsigned long)__kretprobe_trampoline; -} -NOKPROBE_SYMBOL(arch_prepare_kretprobe); - static int try_to_emulate(struct kprobe *p, struct pt_regs *regs) { int ret; @@ -395,49 +385,6 @@ no_kprobe: NOKPROBE_SYMBOL(kprobe_handler); /* - * Function return probe trampoline: - * - init_kprobes() establishes a probepoint here - * - When the probed function returns, this probe - * causes the handlers to fire - */ -asm(".global __kretprobe_trampoline\n" - ".type __kretprobe_trampoline, @function\n" - "__kretprobe_trampoline:\n" - "nop\n" - "blr\n" - ".size __kretprobe_trampoline, .-__kretprobe_trampoline\n"); - -/* - * Called when the probe at kretprobe trampoline is hit - */ -static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) -{ - unsigned long orig_ret_address; - - orig_ret_address = __kretprobe_trampoline_handler(regs, NULL); - /* - * We get here through one of two paths: - * 1. by taking a trap -> kprobe_handler() -> here - * 2. by optprobe branch -> optimized_callback() -> opt_pre_handler() -> here - * - * When going back through (1), we need regs->nip to be setup properly - * as it is used to determine the return address from the trap. - * For (2), since nip is not honoured with optprobes, we instead setup - * the link register properly so that the subsequent 'blr' in - * __kretprobe_trampoline jumps back to the right instruction. - * - * For nip, we should set the address to the previous instruction since - * we end up emulating it in kprobe_handler(), which increments the nip - * again. - */ - regs_set_return_ip(regs, orig_ret_address - 4); - regs->link = orig_ret_address; - - return 0; -} -NOKPROBE_SYMBOL(trampoline_probe_handler); - -/* * Called after single-stepping. p->addr is the address of the * instruction whose first byte has been replaced by the "breakpoint" * instruction. To avoid the SMP problems that can occur when we @@ -539,19 +486,9 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr) } NOKPROBE_SYMBOL(kprobe_fault_handler); -static struct kprobe trampoline_p = { - .addr = (kprobe_opcode_t *) &__kretprobe_trampoline, - .pre_handler = trampoline_probe_handler -}; - -int __init arch_init_kprobes(void) -{ - return register_kprobe(&trampoline_p); -} - int arch_trampoline_kprobe(struct kprobe *p) { - if (p->addr == (kprobe_opcode_t *)&__kretprobe_trampoline) + if (p->addr == (kprobe_opcode_t *)&arch_rethook_trampoline) return 1; return 0; diff --git a/arch/powerpc/kernel/optprobes.c b/arch/powerpc/kernel/optprobes.c index 004fae2044a3..c0b351d61058 100644 --- a/arch/powerpc/kernel/optprobes.c +++ b/arch/powerpc/kernel/optprobes.c @@ -56,7 +56,7 @@ static unsigned long can_optimize(struct kprobe *p) * has a 'nop' instruction, which can be emulated. * So further checks can be skipped. */ - if (p->addr == (kprobe_opcode_t *)&__kretprobe_trampoline) + if (p->addr == (kprobe_opcode_t *)&arch_rethook_trampoline) return addr + sizeof(kprobe_opcode_t); /* diff --git a/arch/powerpc/kernel/rethook.c b/arch/powerpc/kernel/rethook.c new file mode 100644 index 000000000000..5f5f47ae82cf --- /dev/null +++ b/arch/powerpc/kernel/rethook.c @@ -0,0 +1,73 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * PowerPC implementation of rethook. This depends on kprobes. + */ + +#include <linux/kprobes.h> +#include <linux/rethook.h> + +/* + * Function return trampoline: + * - init_kprobes() establishes a probepoint here + * - When the probed function returns, this probe + * causes the handlers to fire + */ +asm(".global arch_rethook_trampoline\n" + ".type arch_rethook_trampoline, @function\n" + "arch_rethook_trampoline:\n" + "nop\n" + "blr\n" + ".size arch_rethook_trampoline, .-arch_rethook_trampoline\n"); + +/* + * Called when the probe at kretprobe trampoline is hit + */ +static int trampoline_rethook_handler(struct kprobe *p, struct pt_regs *regs) +{ + return !rethook_trampoline_handler(regs, regs->gpr[1]); +} +NOKPROBE_SYMBOL(trampoline_rethook_handler); + +void arch_rethook_prepare(struct rethook_node *rh, struct pt_regs *regs, bool mcount) +{ + rh->ret_addr = regs->link; + rh->frame = regs->gpr[1]; + + /* Replace the return addr with trampoline addr */ + regs->link = (unsigned long)arch_rethook_trampoline; +} +NOKPROBE_SYMBOL(arch_rethook_prepare); + +/* This is called from rethook_trampoline_handler(). */ +void arch_rethook_fixup_return(struct pt_regs *regs, unsigned long orig_ret_address) +{ + /* + * We get here through one of two paths: + * 1. by taking a trap -> kprobe_handler() -> here + * 2. by optprobe branch -> optimized_callback() -> opt_pre_handler() -> here + * + * When going back through (1), we need regs->nip to be setup properly + * as it is used to determine the return address from the trap. + * For (2), since nip is not honoured with optprobes, we instead setup + * the link register properly so that the subsequent 'blr' in + * arch_rethook_trampoline jumps back to the right instruction. + * + * For nip, we should set the address to the previous instruction since + * we end up emulating it in kprobe_handler(), which increments the nip + * again. + */ + regs_set_return_ip(regs, orig_ret_address - 4); + regs->link = orig_ret_address; +} +NOKPROBE_SYMBOL(arch_rethook_fixup_return); + +static struct kprobe trampoline_p = { + .addr = (kprobe_opcode_t *) &arch_rethook_trampoline, + .pre_handler = trampoline_rethook_handler +}; + +/* rethook initializer */ +int __init arch_init_kprobes(void) +{ + return register_kprobe(&trampoline_p); +} diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c index e6a958a5da27..90882b5175cd 100644 --- a/arch/powerpc/kernel/stacktrace.c +++ b/arch/powerpc/kernel/stacktrace.c @@ -21,6 +21,7 @@ #include <asm/processor.h> #include <linux/ftrace.h> #include <asm/kprobes.h> +#include <linux/rethook.h> #include <asm/paca.h> @@ -133,12 +134,13 @@ int __no_sanitize_address arch_stack_walk_reliable(stack_trace_consume_fn consum * arch-dependent code, they are generic. */ ip = ftrace_graph_ret_addr(task, &graph_idx, ip, stack); -#ifdef CONFIG_KPROBES + /* * Mark stacktraces with kretprobed functions on them * as unreliable. */ - if (ip == (unsigned long)__kretprobe_trampoline) +#ifdef CONFIG_RETHOOK + if (ip == (unsigned long)arch_rethook_trampoline) return -EINVAL; #endif |